#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int main(int argc, char* argv[])
{
    if (argc != 2)
    {
        printf("can not execute!\n");
        exit(1);
    }
    //MY_105_VAL这个环境变量并不存在
    printf("获取环境变量：MY_105_VAL: %s\n",getenv("MY_105_VAL"));

    if (strcmp(argv[1], "-a") == 0)
    {
        printf("hello a!\n");
    }
    else if (strcmp(argv[1], "-b") == 0)
    {
        printf("hello b!\n");
    }
    else
    {
        printf("default!\n");
    }
    return 0;
}
